CHAPTER ONE
Module I Endocrinology
1. Diabetes Mellitus
A. Type I Diabetes Mellitus
Etiology and Pathophysiology
◦ Diabetes mellitus type 1 is an autoimmune disease. The autoimmune process begins
many years before clinical detection and presentation. It is directly against beta cell of the
islets of Langerhans. The destruction must be very heavy, more then 90 percent of beta
cells must be destroyed for clinical symptoms to develop. The speed of the beta cell
destruction is variable. What is a trigger for autoimmune destruction is not known. Some
authors have speculated about several viruses and other environmental factors in
genetically susceptible individuals.
Onset of disease
◦ Excessive urination, urination at night, thirst, dehydration. The kidneys are not able to return
glucose back to blood when glucose increases above certain level. As a result, glucose appears in
urine, taking with it lots of water. This results in frequent and excessive urination, which in turn
causes intense thirst and dehydration and mineral loss.
◦ Weight loss. Because of the insufficient level of insulin, glucose cannot be used as a energy
source. The body of a patient with IMDM therefore has to use fat and muscles, which results in
weight loss.
Clinical Manifestations
Fatigue and weakness may be caused by muscle wasting from the catabolic state of
insulin deficiency, hypovolemia, and hypokalemia. Muscle cramps are caused by
electrolyte imbalance. Blurred vision results from the effect of the hyperosmolar state on
the lens and vitreous humor. Glucose and its metabolites cause osmotic swelling of the
lens, altering its normal focal length. Symptoms at the time of the first clinical
presentation can usually be traced back several days to several weeks. However, beta-cell
destruction may have started months, or even years, before the onset of clinical
symptoms.
Diagnostic Studies
◦ Glycated hemoglobin (A1C) test. This blood test indicates your average blood sugar level for
the past two to three months. It measures the percentage of blood sugar attached to hemoglobin,
the oxygen-carrying protein in red blood cells. The higher your blood sugar levels, the more
hemoglobin you'll have with sugar attached. An A1C level of 6.5 percent or higher on two
separate tests indicates that you have diabetes.
◦ Random blood sugar test. A blood sample will be taken at a random time. Regardless of when
,you last ate, a random blood sugar level of 200 milligrams per deciliter (mg/dL) — 11.1
millimoles per liter (mmol/L) — or higher suggests diabetes.
◦ Fasting blood sugar test. A blood sample will be taken after an overnight fast. A fasting
blood sugar level between 100 and 125 mg/dL (5.6 and 6.9 mmol/L) is considered
prediabetes. If it's 126 mg/dL (7 mmol/L) or higher on two separate tests, you'll be
diagnosed with diabetes.
Drug Therapy
◦ Type 2 diabetes (or Non Insulin Dependent Diabetes Mellitus (NIDDM)) patients may be
able to control their blood glucose levels by carefully following a diet and exercise
program and losing excess weight. If this first-line treatment does not control blood sugar
levels effectively, an oral medication can be added to the treatment plan. In certain
circumstances, patients with Type 2 diabetes may also need insulin injections. Many
patients with diabetes also need to take medicine to control their blood pressure and
cholesterol levels. Weight loss medications such as Xenical can help with the
management of obesity.
Types of Insulin
There are several types of insulin. These types are classified according to how quickly the insulin
begins to work and how long it remains active.
Meal-time insulin
The goal of mealtime insulin, is to mimic the release of insulin from the pancreas after eating so
that your blood glucose can stay within the recommended range—helping to reduce a spike from
the carbs you consume. It works quickly, but only lasts for about 3 to 6 hours. It's important to
remember that different individuals, depending on metabolism and physical activity, require
different doses to get their blood sugar within the target range. Some get by on less, while others
require more. Your healthcare professional will work with you to determine how many carbs you
should be eating during mealtime and the mealtime insulin dose that corresponds with it.
Long or intermediate (basal) Background insulin
Basal insulin is the background insulin that is normally supplied by the pancreas and is present
24 hours a day, whether or not the person eats. Long-acting basal insulins, such as NPH,
Levemir, and Lantus, begin working in 1-2 hours but are released slowly so they can last up to
24 hours, providing that background insulin that is needed around the clock.
Storage of insulin
Although manufacturers recommend storing your insulin in the refrigerator,
injecting cold insulin can sometimes make the injection more painful. To avoid
, this, many providers suggest storing the bottle of insulin you are using at room
temperature. Insulin kept at room temperature will last approximately 1 month.
Remember though, if you buy more than one bottle at a time to save money, store
the extra bottles in the refrigerator. Then, take out the bottle ahead of time so it is
ready for your next injection.
Here are some other tips for storing insulin:
◦ Do not store your insulin near extreme heat or extreme cold.
◦ Never store insulin in the freezer, direct sunlight, or in the glove compartment of a car.
◦ Check the expiration date before using, and don't use any insulin beyond its expiration
date.
Examine the bottle closely to make sure the insulin looks normal before you draw the
insulin into the syringe.
Administration of Insulin
Dose preparation
Before each injection, the insulin label should be verified to avoid injecting an incorrect insulin.
The hands and the injection site should be clean. For all insulin preparations, except rapid- and
short-acting insulin and insulin glargine, the vial or pen should be gently rolled in the palms of
the hands (or shaken gently) to resuspend the insulin. An amount of air equal to the dose of
insulin required should first be drawn up and injected into the vial to avoid creating a vacuum.
For a mixed dose, putting sufficient air into both bottles before drawing up the dose is important.
When mixing rapid- or short-acting insulin with intermediate- or long-acting insulin, the clear
rapid- or short-acting insulin should be drawn into the syringe first.
After the insulin is drawn into the syringe, the fluid should be inspected for air bubbles. One or
two quick flicks of the forefinger against the upright syringe should allow the bubbles to escape.
Air bubbles themselves are not dangerous but can cause the injected dose to be decreased.
Injection procedures
Injections are made into the subcutaneous tissue. Most individuals are able to lightly grasp a fold
of skin, release the pinch, then inject at a 90° angle. Thin individuals or children can use short
needles or may need to pinch the skin and inject at a 45° angle to avoid intramuscular injection,
especially in the thigh area. Routine aspiration (drawing back on the injected syringe to check for
blood) is not necessary. Particularly with the use of insulin pens, the needle should be embedded
within the skin for 5 s after complete depression of the plunger to ensure complete delivery of
the insulin dose.Patients should be aware that air bubbles in an insulin pen can reduce the rate of
insulin flow from the pen; underdelivery of insulin can occur when air bubbles are present, even
if the needle remains under the skin for as long as 10 s after depressing the plunger. Air can enter
the insulin pen reservoir during either manufacture or filling if the needle is left on the pen
between injections. To prevent this potential problem, avoid leaving a needle on a pen between
injections and prime the needle with 2 units of insulin before injection.
If an injection seems especially painful or if blood or clear fluid is seen after withdrawing the
needle, the patient should apply pressure for 5–8 s without rubbing. Blood glucose monitoring
, should be done more frequently on a day when this occurs. If the patient suspects that a
significant portion of the insulin dose was not administered, blood glucose should be checked
within a few hours of the injection. If bruising, soreness, welts, redness, or pain occur at the
injection site, the patient’s injection technique should be reviewed by a physician or diabetes
educator. Painful injections may be minimized by the following:
◦ Injecting insulin at room temperature.
◦ Making sure no air bubbles remain in the syringe before injection.
◦ Waiting until topical alcohol (if used) has evaporated completely before injection.
◦ Keeping muscles in the injection area relaxed, not tense, when injecting.
◦ Penetrating the skin quickly.
◦ Not changing direction of the needle during insertion or withdrawal.
◦ Not reusing needles.
Some individuals may benefit from the use of prefilled syringes (e.g., the visually impaired,
those dependent on others for drawing their insulin, or those traveling or eating in restaurants).
Prefilled syringes are stable for up to 30 days when kept in a refrigerator. If possible, the syringes
should be stored in a vertical position, with the needle pointing upward, so that suspended insulin
particles do not clog the needle. The predrawn syringe should be rolled between the hands before
administration. A quantity of syringes may be premixed and stored. The effect of premixing of
insulins on glycemic control should be assessed by a physician, based on blood glucose results
obtained by the patient. When premixing is required, consistency of technique and careful blood
glucose monitoring are especially important.
Insulin syringe needle sizes
Conventional insulin administration involves subcutaneous injection
with syringes marked in insulin units. There may be differences in the
way units are indicated, depending on the size of the syringe and the
manufacturer. Insulin syringes are manufactured with 0.3-, 0.5-, 1-,
and 2-ml capacities. Several lengths of needles are available. Blood
glucose should be monitored when changing from one length to
another to assess for variability of insulin absorption. Regulations
governing the purchase of syringes vary greatly from one state to
another.
Site rotation
Module I Endocrinology
1. Diabetes Mellitus
A. Type I Diabetes Mellitus
Etiology and Pathophysiology
◦ Diabetes mellitus type 1 is an autoimmune disease. The autoimmune process begins
many years before clinical detection and presentation. It is directly against beta cell of the
islets of Langerhans. The destruction must be very heavy, more then 90 percent of beta
cells must be destroyed for clinical symptoms to develop. The speed of the beta cell
destruction is variable. What is a trigger for autoimmune destruction is not known. Some
authors have speculated about several viruses and other environmental factors in
genetically susceptible individuals.
Onset of disease
◦ Excessive urination, urination at night, thirst, dehydration. The kidneys are not able to return
glucose back to blood when glucose increases above certain level. As a result, glucose appears in
urine, taking with it lots of water. This results in frequent and excessive urination, which in turn
causes intense thirst and dehydration and mineral loss.
◦ Weight loss. Because of the insufficient level of insulin, glucose cannot be used as a energy
source. The body of a patient with IMDM therefore has to use fat and muscles, which results in
weight loss.
Clinical Manifestations
Fatigue and weakness may be caused by muscle wasting from the catabolic state of
insulin deficiency, hypovolemia, and hypokalemia. Muscle cramps are caused by
electrolyte imbalance. Blurred vision results from the effect of the hyperosmolar state on
the lens and vitreous humor. Glucose and its metabolites cause osmotic swelling of the
lens, altering its normal focal length. Symptoms at the time of the first clinical
presentation can usually be traced back several days to several weeks. However, beta-cell
destruction may have started months, or even years, before the onset of clinical
symptoms.
Diagnostic Studies
◦ Glycated hemoglobin (A1C) test. This blood test indicates your average blood sugar level for
the past two to three months. It measures the percentage of blood sugar attached to hemoglobin,
the oxygen-carrying protein in red blood cells. The higher your blood sugar levels, the more
hemoglobin you'll have with sugar attached. An A1C level of 6.5 percent or higher on two
separate tests indicates that you have diabetes.
◦ Random blood sugar test. A blood sample will be taken at a random time. Regardless of when
,you last ate, a random blood sugar level of 200 milligrams per deciliter (mg/dL) — 11.1
millimoles per liter (mmol/L) — or higher suggests diabetes.
◦ Fasting blood sugar test. A blood sample will be taken after an overnight fast. A fasting
blood sugar level between 100 and 125 mg/dL (5.6 and 6.9 mmol/L) is considered
prediabetes. If it's 126 mg/dL (7 mmol/L) or higher on two separate tests, you'll be
diagnosed with diabetes.
Drug Therapy
◦ Type 2 diabetes (or Non Insulin Dependent Diabetes Mellitus (NIDDM)) patients may be
able to control their blood glucose levels by carefully following a diet and exercise
program and losing excess weight. If this first-line treatment does not control blood sugar
levels effectively, an oral medication can be added to the treatment plan. In certain
circumstances, patients with Type 2 diabetes may also need insulin injections. Many
patients with diabetes also need to take medicine to control their blood pressure and
cholesterol levels. Weight loss medications such as Xenical can help with the
management of obesity.
Types of Insulin
There are several types of insulin. These types are classified according to how quickly the insulin
begins to work and how long it remains active.
Meal-time insulin
The goal of mealtime insulin, is to mimic the release of insulin from the pancreas after eating so
that your blood glucose can stay within the recommended range—helping to reduce a spike from
the carbs you consume. It works quickly, but only lasts for about 3 to 6 hours. It's important to
remember that different individuals, depending on metabolism and physical activity, require
different doses to get their blood sugar within the target range. Some get by on less, while others
require more. Your healthcare professional will work with you to determine how many carbs you
should be eating during mealtime and the mealtime insulin dose that corresponds with it.
Long or intermediate (basal) Background insulin
Basal insulin is the background insulin that is normally supplied by the pancreas and is present
24 hours a day, whether or not the person eats. Long-acting basal insulins, such as NPH,
Levemir, and Lantus, begin working in 1-2 hours but are released slowly so they can last up to
24 hours, providing that background insulin that is needed around the clock.
Storage of insulin
Although manufacturers recommend storing your insulin in the refrigerator,
injecting cold insulin can sometimes make the injection more painful. To avoid
, this, many providers suggest storing the bottle of insulin you are using at room
temperature. Insulin kept at room temperature will last approximately 1 month.
Remember though, if you buy more than one bottle at a time to save money, store
the extra bottles in the refrigerator. Then, take out the bottle ahead of time so it is
ready for your next injection.
Here are some other tips for storing insulin:
◦ Do not store your insulin near extreme heat or extreme cold.
◦ Never store insulin in the freezer, direct sunlight, or in the glove compartment of a car.
◦ Check the expiration date before using, and don't use any insulin beyond its expiration
date.
Examine the bottle closely to make sure the insulin looks normal before you draw the
insulin into the syringe.
Administration of Insulin
Dose preparation
Before each injection, the insulin label should be verified to avoid injecting an incorrect insulin.
The hands and the injection site should be clean. For all insulin preparations, except rapid- and
short-acting insulin and insulin glargine, the vial or pen should be gently rolled in the palms of
the hands (or shaken gently) to resuspend the insulin. An amount of air equal to the dose of
insulin required should first be drawn up and injected into the vial to avoid creating a vacuum.
For a mixed dose, putting sufficient air into both bottles before drawing up the dose is important.
When mixing rapid- or short-acting insulin with intermediate- or long-acting insulin, the clear
rapid- or short-acting insulin should be drawn into the syringe first.
After the insulin is drawn into the syringe, the fluid should be inspected for air bubbles. One or
two quick flicks of the forefinger against the upright syringe should allow the bubbles to escape.
Air bubbles themselves are not dangerous but can cause the injected dose to be decreased.
Injection procedures
Injections are made into the subcutaneous tissue. Most individuals are able to lightly grasp a fold
of skin, release the pinch, then inject at a 90° angle. Thin individuals or children can use short
needles or may need to pinch the skin and inject at a 45° angle to avoid intramuscular injection,
especially in the thigh area. Routine aspiration (drawing back on the injected syringe to check for
blood) is not necessary. Particularly with the use of insulin pens, the needle should be embedded
within the skin for 5 s after complete depression of the plunger to ensure complete delivery of
the insulin dose.Patients should be aware that air bubbles in an insulin pen can reduce the rate of
insulin flow from the pen; underdelivery of insulin can occur when air bubbles are present, even
if the needle remains under the skin for as long as 10 s after depressing the plunger. Air can enter
the insulin pen reservoir during either manufacture or filling if the needle is left on the pen
between injections. To prevent this potential problem, avoid leaving a needle on a pen between
injections and prime the needle with 2 units of insulin before injection.
If an injection seems especially painful or if blood or clear fluid is seen after withdrawing the
needle, the patient should apply pressure for 5–8 s without rubbing. Blood glucose monitoring
, should be done more frequently on a day when this occurs. If the patient suspects that a
significant portion of the insulin dose was not administered, blood glucose should be checked
within a few hours of the injection. If bruising, soreness, welts, redness, or pain occur at the
injection site, the patient’s injection technique should be reviewed by a physician or diabetes
educator. Painful injections may be minimized by the following:
◦ Injecting insulin at room temperature.
◦ Making sure no air bubbles remain in the syringe before injection.
◦ Waiting until topical alcohol (if used) has evaporated completely before injection.
◦ Keeping muscles in the injection area relaxed, not tense, when injecting.
◦ Penetrating the skin quickly.
◦ Not changing direction of the needle during insertion or withdrawal.
◦ Not reusing needles.
Some individuals may benefit from the use of prefilled syringes (e.g., the visually impaired,
those dependent on others for drawing their insulin, or those traveling or eating in restaurants).
Prefilled syringes are stable for up to 30 days when kept in a refrigerator. If possible, the syringes
should be stored in a vertical position, with the needle pointing upward, so that suspended insulin
particles do not clog the needle. The predrawn syringe should be rolled between the hands before
administration. A quantity of syringes may be premixed and stored. The effect of premixing of
insulins on glycemic control should be assessed by a physician, based on blood glucose results
obtained by the patient. When premixing is required, consistency of technique and careful blood
glucose monitoring are especially important.
Insulin syringe needle sizes
Conventional insulin administration involves subcutaneous injection
with syringes marked in insulin units. There may be differences in the
way units are indicated, depending on the size of the syringe and the
manufacturer. Insulin syringes are manufactured with 0.3-, 0.5-, 1-,
and 2-ml capacities. Several lengths of needles are available. Blood
glucose should be monitored when changing from one length to
another to assess for variability of insulin absorption. Regulations
governing the purchase of syringes vary greatly from one state to
another.
Site rotation
